The earliest web sites consisted of static pages containing content such as journal articles and essays. Every user who visited such sites was presented with the same content. Such web sites, therefore, provided an experience similar to reading a copy of a printed book or newspaper.
Not long after the advent of the World Wide Web, however, technology was developed which made it possible to personalize certain aspects of web site content. Some of the earliest incarnations of such personalization technologies enabled users to specify the categories of content to appear on a web page (such as sections for news, weather, sports, and entertainment), and to specify where on the web page each such category of content was to appear, such as by dragging the weather section to the upper left of the page and the sports section to the upper right. After such an initial setup, each user would be presented with his or her own personalized version of the page in which both the content and the layout of the page varied from user to user.
Since that time, many more technologies have been developed for personalizing both the content that appears on a web page to a particular user and for personalizing other aspects of the web browsing experience. Furthermore, social media applications, such as Facebook and Twitter, enable people to form online social networks and to share content and engage in shared activities with each other online. These and other developments have resulted in an increasingly varied and diverse range of online experience, in which both the content and functionality designed by Internet application developers and the activities and preferences of users themselves combine to influence both the content with which users are presented and the actions that users are able to take online.
One of the features of social media applications that has proven most popular with users and most useful to social media companies is the ability to inform users of certain actions taken by certain other users. For example, Facebook may inform a first user that a second user in the first user's social network has “liked” the Starbucks web site, such as by posting a message saying that “John Smith likes Starbucks” on the first user's Facebook wall. The ability to inform users of the online activity of other users, however, is limited in its ability to provide useful and actionable information.